Casting a movie is a little like editing a book: The work shows mainly when something goes wrong. So even ardent filmgoers may wonder: What does it mean when you see the word “casting” in a credit crawl?

Janet Hirshenson and Jane Jenkins offer answers in A Star Is Found, a brisk, antiphonal memoir of their three decades as Hollywood casting directors. In a sense each woman is a real-life Sam Spade who has found the Maltese Falcon – the star or another treasured performer – for movies ranging from Ferris Bueller’s Day Off to The Da Vinci Code. Each has also tackled more prosaic tasks, such casting an entire Soviet army while on location for Red Dawn in a village in New Mexico. And together they reveal more than how they found stars like Julia Roberts for Mystic Pizza and Daniel Radcliffe for Harry Potter and the Sorcerer’s Stone. Their book brims with solid information not just about casting but about acting – about what makes an audition work, what a second-unit director does, and why actors shouldn’t take it personally when they get rejected for parts.

Hirshenson and Jenkins are frank about the sexism – though they are too polite to use that word – that infects Hollywood casting decisions. Movies are cast from the top down, starting with the male lead: “It’s a cardinal rule in Hollywood that you don’t cast the girl until you’ve got the guy. That’s partly because male actors are more expensive and more powerful, so they’re often granted a say in the choice of a co-star. And it’s partly because women will go to a movie that their boyfriends or husbands want to see, but men won’t necessarily go to a movie that their girlfriends or wives want to see. So unless you’re making a straight-out Chick Flick, you start with the guy. (And if you are making a Click Flick, forget about getting an A-list guy – or an A-list budget.)” And you thought Mark Darcy was exaggerating when he asked Bridget Jones if Backlash didn’t have “rather a lot of special pleading.”

A Star Is Found might have had more bite its authors weren’t still working as casting directors. Hirshenson and Jenkins seem never to have met a famous actor who couldn’t act – at least not one they will name – and they’ve met Patrick Swayze. Nor do they appear to have met a director they didn’t like. Steven Spielberg is “friendly and gracious.” David Lynch is “infinitely intelligent.” Brian De Palma is “just terrific.” And so on. Nobody needs another You’ll Never Eat Lunch in This Town Again. But A Star Is Found could have used some of the boldness screenwriter William Goldman showed in his classic memoir, Adventures in the Screen Trade when he summed up the film industry in its scathing signature line: “Nobody knows anything.”

Even so, it’s refreshing to read a book by Hollywood insiders who assert credibly that they owe their success to “kindness and courtesy” and would never keep an actor waiting for two hours without an apology, as some casting directors do. Hirshenson and Jenkins, you suspect, need not fear for their lunch reservations.

Best line: Jenkins on the price that female stars pay for getting older: “Sally Field, whose love interest was the somewhat younger Tom Hanks in 1988’s Punchline, when she was all of 42, went on to play Tom’s mother in Forrest Gump. I think that pretty much says it all.”

Worst line: Hirshenson on auditioning Tom Cruise for The Outsiders: “He was only 19 back then, but he already seemed to have an incredible drive and inexhaustible enthusiasm. You could tell he was game to do anything that the picture needed, and that he had a powerful long-term vision of the kind of work he wanted to do.” Like jumping on Oprah’s couch? Lines like this beg for more a lighter – if not frankly satirical – touch.

Recommended if … you’re looking for a fine holiday gift for a movie fan, aspiring actor, or a school drama coach.

Caveat reader: This review was based on an advance readers’ edition. Some material in the final edition may differ.